Should I blend the oats homogeneously with the other grains while dry to prevent a blob of oats from forming wherever they happen to fall in the mash tun. I know they like to clump.
You could, sure, but simply stirring the mash should disperse them sufficiently, preventing excessive clumping, I'd say. The past few years I've been
underletting the mash (learned from the LoDO guys), and have had far less clumping too because of that.
I run flaked/rolled adjuncts through the mill, usually at the tighter, 0.025" gap, the same used for wheat malt. It pulverizes them, which helps with faster hydration and possibly conversion.
What about using malted oats, is there a substitution factor that you can reccomend when a recipe calls for rolled?
Malted oat kernels are awfully small, needle-like grains with a leathery husk. I mill/crush them on an even tighter gap (around 0.016-018") than wheat or rye malt and flaked goods. The knurls are almost touching!
When looking at oat malt kernels, you surely get the impression there's as much or even more husk as there's endosperm. It's surprising to me that rolled oats are the size they are, given the small endosperm. I don't recall ever seeing raw (unmalted) oats. Maybe the malting/kilning process shrinks the kernels? I may need to hand crush some and see what they actually yield.
Now you mentioned it, it's probably justified, due to the husk content, to use more oat malt than flaked oats (by weight). Could well be an additional 50%... hmm.
Since I was finally able to get a sack of malted oats, I've been using them in NEIPAs instead of rolled oats, substituted 1 for 1. I can't really tell if the malt makes a difference flavorwise compared to rolled/flaked. Perhaps they help with a more persistent haze, which would need to be tested to make the claim.
I've also brewed with Triticale (it's a wheat/rye crossbreed) another small, narrow, needle-like grain that needs it's own crush setting.
